A low-pressure system and associated front are bringing widespread rain across Japan from the west to the east this Saturday [1, 2].
The arrival of the rainy season in these regions typically signals a period of increased precipitation and humidity that affects agriculture and transportation infrastructure across the archipelago.
According to the Japan Meteorological Agency and regional forecasters, the Hokuriku region is expected to enter the rainy season around June 20, 2026 [1, 4]. Reports regarding southern Tohoku vary; some sources indicate the region is entering the rainy season on June 20, while others suggest it will occur around June 21, 2026 [1, 4].
In the Kanto region, rain is expected to begin around midday on June 20 [1, 2]. While some forecasts suggest rain will become more frequent from June 21 onward, the immediate impact remains a low-pressure system moving across the country [1, 3].
"A low-pressure system accompanied by a front will bring rain across a wide area from western to eastern Japan," a TBS NEWS DIG weather caster said [2].
The weather shift is also impacting temperatures. In Nagoya, the daytime temperature is forecast to be 25 °C, which is nine °C lower than the previous day [1].
Weather officials said that the front will extend from western Japan to the vicinity of eastern Japan during the middle of the week [3]. This system is driving the current precipitation patterns affecting the Pacific coastal areas and inland regions alike [1, 3].
“Hokuriku region expected to enter the rainy season around June 20, 2026”
The transition into the rainy season for Hokuriku and southern Tohoku marks a critical seasonal shift for Japan's climate. The presence of a strong low-pressure system moving from west to east suggests a high probability of concentrated rainfall, which often increases the risk of landslides and flooding in mountainous regions and urban centers like Kanto.
